Block forming apparatus



Feb. 12, 1952 G', A VESPE-R 2,585,193

BLOCK FORMING APPARATUS Filed Dec. 4, 1947 s Sheets-Sheet 1 7 ENTOR.

BY W 6 am meuey Feb. 12, 1952 G. A. VESPER BLOCK FORMING APPARATUS 6 Sheets-Sheet 2 Filed Dec. 4, 1947,

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UTTOENE'V Feb. 12, 1952 e. A. VESPER BLOCK FORMING APPARATUS 6 Sheets-Sheet 3 Filed Dec. 4, 1947 INVENTOR. K W 6 1 a. wash HTTOENEV Feb. 12, 1952 G. A. VESPER BLOCK FORMING APPARATUS '6 Sheets-Sheet 4 Filed Dec. 4, 1947 INVENTOR. ea.

HTTOENEV Feb. 12, 1952 G. A. VESPER BLQCK FORMING APPARATUS 6 Sheets-Sheet 5 Filed Dec. 4, 1947 UTTOZNEV Feb. 12, 1952 VESPER 2,585,193

BLOCK FORMING APPARATUS Filed D80. 4, 1947 6 Sheets-Sheet 6 I'll IN V EN TOR.

Patented Feb. 12, 1952 UNITED trnrss FATE NT 40F F 1 cs .BLQCK FORMING. APPARATUS George A.Vesper, "Los Angelcs, Calif.

Application December 4, 19.47, SerialrNo. 789,-706

(Cl..l2584) 3 Claims. ll

invention relates .toa machine .ior .iorm- ,ing "blocks and .the like Jirom fcomm'inuted Jfiuent material; more particularly it relates to a machine for forming blocks, tile and theilike from a fluent cementitious aggregate.

It is an object of this invention to provide an improved machine for this purpose.

It'is another object of this invention to provide a machine capable of producing uniform and accurately shaped blocks.

Itis another object of this invention to provide a machine utilizing ressure for compacting the blocks, having novel means for applying the pressure to "the molded material.

It is another object of this invention to provide such a "machine "having novel means for altering the amount of compaction pplied.

It is another object of this invention to provide a block forming machine having "novel means for removing the blocks after the forming 'op'eration.

It is anotherobject of this invention to provide a concrete block forming machine having *noxifil means =for removing the blocks from the mo i it is another object of this invention to provide a concrete block forming machine employing a stationary 'mold 'so arranged as to be read- My loaded and "unloaded.

This invention possesses many other advantages and has other objects "which may be made more easily apparent a consideration of one embodiment :of the invention. For "this purpose there is shown a 'form in the drawings;

accompanying and forming :part of the present specification. This :form will now be :described in :detail,;illustrating the general principles vof the invention; but it is to be understood that this -detaileddescription isnot to be taken in a limiting sense, since the :scope (of the invention showing the parts in va di fierent operating position;

Figure .4 is a .tragmentary orosssection @showing the mold cover and operating mechanism therefor, taken substantially as indicated by :line-ib-al of1Figu-re3;

.ly numbered :linesion Figure l;

2 Figure 5 .is .a fragmentary longitudinal section-showing themold .cover and the mold, taken substantially .-as indicated by .lines 5- 57 of Figure 3;

Figures 6 and 17 :are .transverse sections, taken substantially .as indicated by the corresponding- Figure 8 is a schematic .vieW showing the hydraulic operatingmeans for the machinefl .Eigures -8-a, 8-1)v and 8-0 are fragmentary views showing portions of the :hydraulic system of Figure 8, under !different operating conditions; and 1 Figure .9 is an isometric view .of a finished :block.

The machine comprises ;a stationary .horizontal mold M with a-movable bottom member 13 arranged to traverse substantially the entire depth of the mold, .and ;a top closure member .or head C movable between a position closing the mold and a position in which v the :top .of the mold is open and substantially unobstructed. .In operation, the :bottom member .13 is retracted to an initial or lower position at 3. predetermined depth below the top iof the mold, and the mold M is filled with the cementitiousaggregate .orother material to be formed. The head C is :then moved to closed position, being so "arranged :as to extend rinto the mold andtinitial-ly :compress the .material. c m The means .for moving the head exerts a large force .on the head :asit approaches closed position, :and when the closure or head .-is in 'closed position, is capable of resisting a large force urging the "head :to open. The bottom member B is then urged upwardly to a definite position in the mold compressing the material against the head, and forming a tb'lock-or blocks of a-predet'ermined thickness. 7 v v After the bottom member B :has completed the compression of the iblook, :the head is returned to open position; *the :bottom member then .moving upwardly to :force the blocks rout of the mold and supporting them :ior'iremoval by any suitable means.

"Means are providedior alteringithe amount of compaction to =which the aggregate is subjected. For this purpose, the iriitial -:or lower :position of the bottom member B is made vertically adjustable. Sincethe mold M is always filled flevel'iwith 'itstop, thefinitial'position of the bottom member 13, determines the amount-ofaggregate iii the :mold. Thus, since the bottom Bis always moved to the same distance "below the head C'at the completion of "its compressive stroke to *form ;a

block of standard thickness or depth, the density of the block depends upon the amount of material in the mold. Means are also provided for adjusting the spacing between the head C and the bottom member B at the completion of the compressive stroke, so as to form blocks of a difierent thickness as required.

It is to be understood that the adjustment of the initial position of the bottom member B is to be made with due regard to the characteristics of the aggregate or material to insure the desired amount of compression upon compaction to the predetermined thickness.

Referring in detail to the machine, the mold M as shown in Figures 2, 4 and5 comprises a rectangular space 5 with vertical side walls 6, l. 8 and 9 formed in any convenient manner, for example, by structural iron members "L. H, l2 and I3 of channel shaped cross-section of suitable depth. These members IO, N, |2 and I3 are appropriately joined as by welding their adjacent corners, and are supported by the frame F of the machine. The side walls 6, 1, 8 and 9 may be provided with liners or protective plates 8-a, 1-a, 8-a and 9-1; respectively.

The mold M may be divided by appropriate cross walls to form blocks of a desired size, suitable cores being provided to form hollow blocks. By way of example, the mold space 5 is shown as divided into three mold spaces M-l, to form three rectangular blocks D, one of which is shown in Figure 9. For this purpose, a pair of transverse walls I and I6 suitably secured to the side members I and 9 are provided and a pair of cylindrical cores l1 and I8 are supported in each of the spaces. M-l, by a plate I9 extending between the bottoms of the members 1 and 9. These mold elements may be secured in any appropriate manner, as by bolts and screws, or welding (not shown).

The mold cover or closure head C comprises a backing plate with a plurality of members 2| secured thereon, said members each having an external configuration and core openings 2l-a such that the members 2| are capable of entering to the forward end of each pair of arms 22 and 23 as by pins 28, the other ends of each pair of links 25 and 21 being pivotally joined by a common pin member 29 to an upwardly directed arm 3%, swingably supported by pins 3| suitably secured to a longitudinally extending frame member 32. Each pair of links 26 and 21 together with the associated arm 30 forms a toggle structure T for swinging the cover C between open and closed positions. When the cover is in open position (Figure 2) the top of the mold is entirely clear and unobstructed. When the cover is in closed position the links 26--2'l and arm 30 are aligned (Figure 3), so as to withstand a very great force urging the cover upwardly; also a very large force is exerted by the cover as it approaches closed position.

The means for operating the toggles -T comprises a hydraulic cylinder 33 pivotally secured at its lower end to .a longitudinally extending member 34 of the frame F, and having a piston 35 connected by a piston rod 35-11 to the pin member 29. Admission and discharge of fluid to and from the opposite ends of the cylinder 33 is controlled by valves 36 and 31, as will be more fully described hereinafter. Opening movement of the closure C is limited by the engagement of the toggles T with a bar 38 provided on the frame F.

The movable bottom member B comprises a plurality of plates 40 respectively accommodated in the mold spaces M-I and apertured for the cores I! and. I8, appropriateclearances being provided to permit free movement of the plates. A pallet member 42 of plate metal of suitable thickness rests on each of the plates 40, and is arranged to fit the mold space M-I quite closely, so as to form the bottom closure therefor.

The plates 40 are supported in spaced relation above a vertically movable pressure head 43, by a plurality of posts 44, suitably secured respectively to the plates 40 adjacent the corners thereof. The posts 44 extend through clearance openings provided in the head 43 and are threaded for the reception of nuts 45 and 46 respectively engaging the upper and lower surfaces of the head 43. By adjusting the nuts 45 and 45, the spacing of the plates 40 above the head 43 may be varied, as will be more fully pointed out hereinafter. Thehead 43 is supported for vertical movement in two steps by a dual cylinder hydraulic mechanism 50.

Referring particularly to Figure 3, the mechanism 53 is shown as comprising a main or first cylinder 5| of large diameter having upper and lower heads 52 and. 53 respectively, the upper head 52 having oppositely directed extensions 52-a and 52-b by the aid of which the mechanism is mounted on parallel spaced beams 54 of the frame F. A piston 55 is provided in the cylinder 5|, having a tubular member 56 secured thereto which forms a piston rod extending upwardly through a boss 52-c on the head 52, suitable packing means being provided to seal about the member 56. The upper end of the member 56 is provided with-a closure or head 51, the lower end of member 55 opening into the cylinder 5| below the piston 55. The member 58 forms a supplemental or second cylinder, and has a piston 58 therein secured to the lower end of a rod 59, which extends upwardly through the closure 51 and has the head 43 secured to the upper end thereof.

The' head 51 of the supplemental cylinder 55 is provided with annular extensions or flanges which provide an upper surface 5'|-a for supporting the pressure head 43 when the piston 58 is in its lower or retracted position in cylinder 56 (see Figure 3), and a lower surface 51-!) for supporting the piston 55 in its adjusted lower or initial position.

It will be clear that the position of the plates 40 and pallets '42 in the mold spaces M| below the top of the mold when the pressure head 43 is supported on the surface 5'I-a, will depend upon the height of such initial position. Thus, by adjusting this position, the efi'ective volume of the mold spaces M-l may be altered which will vary the amount'of aggregate provided for each block, since the mold is always filled flush with the top.

Accordingly, adjustable means are provided for limiting the downward movement of the piston 55, etc., and to support the piston 55 in its initial position. The boss 52-c'serves by engagement with the surface 514) to'support the head 43, and the bottom'member B in their lowest adjusted position, as shown diagrammatically in Figure 8.

top head 52 (Figures 3 and 5.).

members 2| always occupy the same position thickness.

To support the head 43 and bottom member 3 athigher positions, one or more spacer rings '60 are placed on the boss 52-0 encircling the member 56, three such rings .60 being shown by way of example'in Figures 2, 3'and 5. To permit' ready placement and removal, the rings 69 are made in halves, and to maintain them in stacked relation they are provided on their opposite edges with tongues69-a and recesses 60-?) adapted for interengagement.

Upward travel of the head 43 and the bottom member B is always terminated at the same point, by engagement of the piston 55 with the Since the cover when closed, the material in the mold spaces M-i will always be compressed to a predetermined Accordingly, adjustment of the initial position of the member B varying the amount of aggregate in the mold spaces M-l will result in altering the amount of compaction of the aggre ate in the finished block.

Adjustment of the rods 44 will alter the Position of the bottom member B at the completion .of theupstrohe, and thus serve to vary the thickness of the finished block D. These rods 44 also enable individual adjustment of the plates 48, as may be required.

.Fluid pressure in the cylinder 5| below the piston 55 also acts on the supplemental piston 58 urging .it upwardly. However, upward movement of the piston 58 with respect to piston 55 is prevented by a body of liquid confined in cylinder 56 between piston 58 and the head 57.

Means are provided for releasing this liquid after the upward stroke of the piston :55 has been completed and the mold cover C swung to open position. Thus, the fluid pressure in the cylinder 5| becomes effective to move piston 58 to the upper limit of its stroke in the cylinder 56,.moving the head 43 and the bottom B further upwardly so that the pallets 42 with the blocks D thereon are supported above the mold M (see Figures 1 and 2). From this position the pallets 42 and blocks D may be readily removed and transported as required for further processing of the blocks.

"To facilitate operation of the machine, it is desirable to provide means for rapidly filling the mold M and for removing the formed blocks D after ejection therefrom. For this purpose, the frame F which supports the mold and pressing apparatus may have oppositely directed longitudinal extensions 'F-i and F-'2, as shown in Fig-::

ure 1.

The frame extension F-J has ahorizontal plate (Figures 1., 5 and '6'), the upper surface of which forms a continuation of the top surface of the mold A shorter plate 1|, supported on the frame F as by brackets '12 forms a similar continuation in the opposite direction. A pair of structural members T3 and 14 supported in parallel spaced relation respectively above the opposite edges of the plate 10 serve to 'rotatably mount rollers 75.

-A rectangular box like member 16 having front and back walls it-a and it-b, side walls lB-c and open top and bottom is supported "by the rollers 15 so that its lower edges are spaced above plate 16 by a suitable clearance, means being provided to cause the member Hi to traverse the mold 'M to a position such as indicated by the broken lines. The loading member "[6 base rear extension 18 with a horizontal plate =19 the *full' width'of the member 16. Spaced parallel rails .80 and M are provided along each side wall 15%! and along the rear portion 18 and cooperate with the rollers 151130 :support the member 16. A hopper '82 orthe like defining a Spaceto receive the aggregate "of which the blocks are to 'gbeuformed is provided on the lframe ,F-I closely spaced above the member 1-6., and opens thereinto. I

The arrangement is such that aggregate A in the hopper 82 substantially fills the space defined by the loading member 16, being supported on the plate 10. Upon movement of the member .76 to the right across the mold'M, the material fills the mold spaces M-l, plate 19 serving to supportthe material in the space 82 at this time. The member .lB is then moved back across the mold M removing the excess material from the mold and receiving additional aggregate from the space 82.

A hydraulic cylinder and piston arran ement 84 controlled' by a valve .85 is provided for moving the member '16. Thus, as shown infiaure 1, theeylinder 84-0. is secured to the'frame extension F4 and has a conventional piston (not shown) attached to the back wall 16-1)- of the ,meember L6 by a piston rod 84-h engaging a pin and clevis 84-0.

The frame extension F-2 comprises a pairlof spaced horizontal members v(Figure 7), each having rail forming means :9! thereon: An oil bearer 92 is provided for removing the 'blocksD after ejection from the mold M and comprises a rectangular frame '93 with rollers 94 on opposite sides thereof supporting the frame 93 forlongitudina'l movement along the rails 91.. A :pair of elongated elements 95 and 9.6 .depend from each side of the frame 93 and are joined attheir lower ends by a horizontal supporting member 9?, each of which has an inwardly directed flange B'I-a.

The arrangement is such that when-the mold bottom member B is in its uppermost position the pallets 42 are spaced sufficiently above the top of the mold M to accommodate the flanges ill-a beneath them, the elements 95' and "96 being of such length that suitable clearance isvprovided between the members 91 and the top of the mold. Further, the pallets 42 overhang the edges of the plates 41] by a short distance, all as shown in Figure 2.

In using the off bearer 92, the blocks D are positioned above the mold, as previously described; the off bearer 92 is then moved to position the flanges Sl-a beneath the pallets 42. The hydraulic means 5| is then operated to lower plates 4E2, allowing the pallets 42 to be supported by the flanges 9'l-ct of the off bearer 92, and the off-bearer moved to the right (Figure ,1) removing the blocks from above the mold M. The blocks B may then be removed from the offbearer 92 for further handling by appropriate means (not shown).

The machine together with the hydraulic operating means and controls therefor are shown schematically in Figures 8, .8a tab and 3-0. Therein a pump of any suitable type indicated by the numeral 190, arran ed to deliver suitable liquid from a sump or reservoir I 0! continuously to a conduit H12 while the machine :is in use. A conventional relief valve 103 is provided .to return the liquid directlywto the ,-.sump ,Hll "in .case pressure in th system reach s :93-

.cessive amount dueto failure or iammlng of the "Parts. J

The control valves 36, 31 and 85 may be four 'way valves of conventional type, and are shown diagrammatically in Figure 8. Thus, referring to valve 36, it is shown as comprising a circular housing 36-a. having oppositely disposed ports I04 and I05, and a fluid pressure inlet and outlet I06 and I! respectively spaced 90 from the ports I04 and I05. A closure member 36-1) is rotatable in fluid tight relation in the housin 36-0 and has a pair of through passages I08 and I09 opening respectively at points spaced 90 about the member 36-17.

In Figure 8 the member 36-h is shown in neutral position, closing ports I04 and I as well as the inlet and outlet I06 and I0I. Rotation of member 36-?) clockwise through an angle of 45 to the position shown in Figure 8-a, establishes communication between port I04 and the outlet I0'I via passage I08, and between port I05 and the inlet I06 via passage I09. Rotation of member 36-17 from theposition of Figure 8, counterclockwise through an angle of 45 to the position of Figure 8-0 establishes communication between port I05 and the outlet I01 via passage I08 and between port I04 and the inlet I06 via passage I08. Valves 3'! and 85 are substantially identical with valve 36, except that the rotatable member in each valve 31, 85, as shown for example in the member 3I-b of valve 31, has a bypass port IIO for connecting the inlet III with the outlet II2 when the member 31-!) is in neutral position.

A valve capable of performing the above function but employing a reciprocable closure instead of an angularly movable closure, is commercially available from Vickers Ltd, being known as a four-way spool valve. In Figures 2, 3 and 4, the valves 36 and 31 are shown as of this type, the piping for conducting fluid to and from the valves being omitted for the sake of clarity.

A reciprocable rod H5 is provided for operating the closure of valve 31, being pivoted to the lower end of a lever IIS pivotally mounted at I I! on the main frame F (see particularly Figure 2). An operating arm I I8 is secured to the lever H6, and by movement upwardly or downwardly from the position shown, serves to operate the valve 31 to perform functions analogous to that described in connection with valve 36 and Figure 8.

The valves 36 and 85 are similarly provided with operating arms IIS and I respectively, and it is preferred that the closure in each valve 36, 3'! and 85 be spring biased to neutral position.

Referring to Figure 8, the closures of valves 36, 31 and 85 are shown in their neutral positions, thus blocking the ports communicating with the ends of cylinders 33, 5I, 56 and 84 respectively controlled by the valves, trapping the liquid and locking the pistons in the cylinders against movement, the member I6 being in retracted position, the mold cover C being open and the pressure head 43 being in its adjusted lower or initial position. Liquid from the pump I00 freely by-passes valve 85 to conduit I2I, through by-pass H0 in valve 31 and via conduit I22 to the sump IOI. Thus, under these conditions the only load in the pump is a small friction head.

The first step in operating the machine requires the filling of the mold M. For this purpose, the closure of valve 85 is operated (turned clockwise through 45 from the position shown in Figure 8) to connect the pump I00, via conduits I02 and I23 to the left hand end of the cylinder 84 and closing the by-pass through the valve 85. Thus, the loading member I6 is caused to traverse the mold M, the liquid in the right hand end of the cylinder 84 discharging through conduits I24 and I2I which were also connected by the clockwise movement of the valve closure, valve 3! and conduit I22 to the sump IOI.

Upon completion of the movement to the right of the loading member 16, the closure of valve 85 is operated (turned counterclockwise through 45 from the position shown in Figure 8) to connect the right hand end of the cylinder 84 to pump I00 via conduit I24 and the left hand thereof to discharge via conduits I23, I2I, valve 31 and conduit I22. This causes the member I6 to return to its initial position, whereupon the valve 85 is returned to neutral connecting condiiit I2I with the pump I00.

After the mold M has been filled, the cover C must be moved to closed position. An important safety feature of this control mechanism is that valves 36 and 31 must be operated simultaneously to close the mold cover. Thus, accidental operation of one valve will not cause the cover C to close with accompanying possibility of injury to the operator. Further, the operator must have a hand on each valve, obviating the possibility of closing the cover while having one hand between the cover and the mold, such as would exist if a single valve controlled the cover movement.

The ports I04 and I05 previously described in connection with the valve 36 are connected respectively with the upper and lower ends of the cover or closure head operating cylinder 33 by conduits I25 and I26. The outlet I0! is connected to conduit I22 and thence to the sump IOI by conduit I21, and the inlet I06 is connected by conduit I28 to a diverter valve I29, adapted to supply liquid under pressure to conduit I28, as will be pointed out presently.

The valve 3! includes the valve body 3'I-a with oppositely disposed ports I35 and I36, spaced from the inlet III and the outlet II2. Port I36 is connected with the lower end of cylinder 5I by conduit I31 and thence with the lower end of cylinder 56 which opens through the bottom of piston 55. The port I35 is connected with the upper end of cylinder 5| by conduit I38. The upper end of cylinder 56 is adapted to communicate with conduit I38 and thence with port I35 by a connection including a check valve I38 and a relief' valve I40. The arrangement is such that when piston 58 is urged upwardly in the cylinder 56 with sufficient force, the relief valve I48 will permit liquid to be discharged allowing piston 58 to move upwardly. Check valve I 38 permits liquid to be returned for urging piston 58 downwardly in cylinder 56.

The diverter valve I29 comprises a body having a horizontal chamber MI in which is a freely movable valve member I42, which may conveniently be a steel ball. Horizontally directed inlet ports I43 and I44 are provided at opposite ends of the chamber I M, and an outlet port I45 extends transversely from the mid-point of the chamber MI. The inlet I06 of valve 36 is connected with port I45 by the conduit I28, the inlet ports I43 and I 44 being connected respectively with conduits I31 and I38 by conduits I41 and To cause the cover C to move to closed position, the valve closure 36-1) is turned 45 clockwise and valve closure 31-1) is turned 45' counterclockwise from the positions shown in Figure 8,

to the positions shown in Figure 8-11. This closes the bypass port IIil and directs liquid under pressure from the conduit I2I to conduit I38 and the upper ends of cylinders5I-and 55. However, since the pistons 55 and 58.,are already at their initial adjusted lower positions from the preceding operation of the press, these pistons do not, move. Liquid under pressure also passes from the conduit I38 via conduit I48 to thediverteif valve I29'urgii1g the closure I52 to close port I53 and opening, port its sothat liquid may enter,

chamber MI and pass via outlet I55, conduit I28, valve 36 and conduit I26 to the lower end of cylinder 53. The upper end of cylinder 35 is connected via conduit I25, valve tfi andconduit I2? to the discharge conduit i22; of cylinders 5| and. 5,5, are co discharge conduit I22 via co valve 37-. v

The pressure in the lover end of the cylinder 35 urges the piston 35. therein upwardly until the links 25-421, of thetoggles T are aligned and the cover C is in closed position, further movement of the piston 35 being prevented by the piston contacting the upper end of the cylinder 33 (see Figure 3). The valve 35 may be allowed to return to neutral position as soon as the cover is closed, since in such position liquid is trapped in both ends of the cylinder 33, preventing return movement of the piston 35, and release of the toggles T.

After the cover C has been. closed the valve 3? is operated to reverse the pressure conditions in the cylinders 5i and 5.5 by connecting conduit I5? with the pressure, conduit IZI, and conduit I38 with the discharge conduit I22, as shown in Figure 8-b, Under these conditions liquid under pressure from conduit, I311 acts inchamber I lI through conduit I l? and port I43 to cause the valve-member I42 to close port I l-. This causes the pistons and 55 to move upwardly together, movement of the piston 58 in cylinder 56 being prevented by liquid trapped therein by the check valve I39 and relief valve I40. This movement continues until piston 55 contacts the upper cylinder head 52 and constitutes the forming or pressing movement, the accompanying movement of the mold bottom member B compressing the material in the mold M against the cover C. The toggles T, provided for holding the cover C closed, enable the cover to withstand a large force against its lower face, urging it to move to open position.

Upon completion of the upward stroke of piston 55, valve 35 is operated to reverse the pressure conditions in the cylinder 33 by connecting conduit I25 with the pressure inlet I06 and conduit I26 with the outlet I01, as shown in Figure 8-0, liquid under pressure passing from the conduit I3! via conduit I41, port I53, valve chamber MI, port I45, and conduit I28 to inlet I05. This liquid pressure acts in the upper end of cylinder 33 to cause piston 35 to break" the toggles T and lift the cover C to open position. This frees the material in the mold M for ejection by a further or supplemental upward movement of the bottom member B, caused by upward movement of the piston 58 in cylinder 56. However, such movement is prevented by the liquid trapped in cylinder 55 above the piston 58. When the cover C is fully open, movement thereof is stopped by engagement of the toggles T with the bar 38 on the frame F. Pressure thereafter builds up until the upward force acting on the piston 58 is sufiicient to cause the trapped liquid in the cylinder 516to, open the relief valve, M0; whereuponthis:

liquid discharges via conduit r38, valve. 31, and. conduit. t-ZZ; This allows the piston, 58,- tomoye upwardly and. cause; thebottom member 3 piston 55,, returnsto its. t al posi on. s de e mined by the ad ustin rings. oil wh ch enga e thesurfamefl br.

Since after compl ion orming: operationl, the. p stons=55 and m stalw ys her tu ned. toth ir initial low-e P ions, before fill ng the mold M ,'it. is possible to. opera e he machine by operating valves 35, and 31 to cause the Cotter; G to close to urge piston 55 and connected parts upwardly.

Due to the fact that. less force is, requ red to, close the cover C than to raise piston 55; head 5.3,, mold bottom B and the materialin the mold M, the cover will close before the. piston 55. Start-.5. to, move up. When the cover is in closed; posia tion, the tbggle links 26-41 and arms 30; are aligned and the piston 35in cylinder fiiiis stopped bil -engagement with the upper head of the cylinv, der $3 as before described. This willcause pre sure to build up in cylinder 51- so that the mold; bot m Bis u s d pw rd y to compr ss the ma teria1 in the mold a ainst the cover Q; the; same manner as before.

It will be seen hat: operation of: the valv 36 while valve 31 is inneutral position will not causemovement f the cov r s nce under ha dition no liquid pressure is present a the i- The valveiil mus be move so that he blipass port iiihiscl sed andpressure s admittedto either conduit I37 or I38 before closing movement of the cover C can occur in response to opening the valve 35. Since valves 35 and 31 are both spring biased to neutral position, both of the operators hands are required for simultaneous operation of the valves.

It is to be understood that conventional means may be provided in connection with any of the hyraulic cylinders and pistons for retarding the piston near the end of its stroke, such means commonly comprising an arrangement whereby the piston at an appropriate point in its stroke reduces the effective area of an outlet port from the cylinder.

I claim:

1. In block forming apparatus: means forming a molding space having vertically extending side walls; a closure head for the upper end of said space, movable between open and closed positions; means for operating said closure head to open and closed positions; a bottom closure member for said space, movable upwardly therethrough; means for moving said member upwardly within the mold to a predetermined point when said head is in closed position, and thereafter, when the head is in open position, for moving said member to project from said space, comprising a first hydraulic cylinder and piston, means whereby said piston supports said member; a second hydraulic cylinder and piston, said second cylinder being connected to move with the first piston, the second piston being connected to move with said member; the spaces in said cylinders below the pistons being in free communication; means for supplying fluid pressure to raise the first piston; means forming a fluid lock preventing relative movement between said second cylinder and piston, whereby said pistons move together; and means for releasing the locking fluid to cause the second piston to move in response to said fluid pressure.

2. In block forming apparatus: means forming a molding space having vertically extending sides; means forming a closure, movable between a. position closing the upper end of said space and an open position; means forming a bottom closure member for said space, movable upwardly therethrough; support means for said member including a cylinder and piston structure; spacer means cooperating with said structure to support said member at an adjusted height in said space to alter the capacity thereof; said structure being operable to move said member upwardly from said position to compact material in said space; stop forming means to limit upward movement of said member by said structure to a predetermined distance below said closure, independent of said adjusted height; and means for thereafter moving said member to extend above the top of said space when said head is in open position, including a second cylinder and piston structure.

3. In block forming apparatus: means forminga molding space having vertically extending side walls; a closure head for the upper end of said space swingably mounted exteriorly along the rear side of the mold for movement between open and closed positions; means for operating said closure head to open and closed positions, comprising a pair of links pivotally joined at their adjacent ends to form an upwardly extending toggle structure, pivoted at its lower end to said 4 head adjacent the forward side of the mold; means forming a frame supporting said mold forming means and including a plurality of ver- 12 tically spaced horizontal members rearwardly of the mold; means pivotally supporting the upper end of said toggle structure on the uppermost of said members; means for moving said links to operate said head interposed between another of said members and the pivotal connection between the links; the other member being adapted to engage said toggle structure and limit its movement in head opening direction; and a bottom closure for said space, movable upwardly to compact material therein against said head.

GEORGE A. VESPER.

REFERENCES CITED The following references are or record in the file of this patent:

UNITED STATES PATENTS Number Name Date 803,016 Palmer Oct. 31, 1904 1,174,885 Macbeth Mar, 7, 1916 1,179,898 Cofiey et a1 Apr. 18, 1916 1,193,507 Brown Aug. 8, 1916 1,501,625 Safiert July 15, 1924 1,777,660 Dahl Oct. 7, 1930 1,842,803 Sexton Jan. 26, 1932 1,851,484 Bausman Mar. 29, 1932 1,860,075 Byerlein et al May 24, 1932 1,925,050 Jagdmann et a1. Aug. 29, 1933 1,939,670 De Mattia Dec. 19, 1933 1,974,837 Shillinger Sept. 25, 1934 2,007,063 Rolland July 2, 1935 2,293,815 Gates Aug. 25, 1942 2,328,071 Jaeckel Aug. 31, 1943 2,342,772 Wellman Feb. 29, 1944 2,455,553 Briscoe Dec. 7, 1948 2,466,339 Turner Apr. 5, 1949 FOREIGN PATENTS Number Country Date 149,077 Great Britain Aug. 9, 1920 548,766 France Oct. 31, 1922 

